Grid data (raster data and imagery) is stored on an evenly spaced grid of cells of uniform dimension. It may represent point samples of a continuously variable manifold, or estimations of the average value of some measurable parameter within the grid cell. It also encompasses geolocated imagery.
The size of gridded datasets has increased substantially over the years and this growth has outstripped the capacity of computing power to manage the grid data. This trend will continue for the foreseeable future. It is necessary, therefore, to design storage formats which help computers to access, visualize and process this data in an efficient and timely fashion.